package com.config.jwt;

import io.jsonwebtoken.Claims;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureException;
import org.springframework.web.filter.GenericFilterBean;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * Created by Yuicon on 2017/3/19.
 */
public class JwtFilter extends GenericFilterBean {

    public static String SECRET_KEY = "yuicon";

    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
            throws IOException, ServletException {

        final HttpServletRequest request = (HttpServletRequest) req;
        final HttpServletResponse response = (HttpServletResponse) res;
        final String authHeader = request.getHeader("authorization");

        if ("OPTIONS".equals(request.getMethod())) {
            response.setStatus(HttpServletResponse.SC_OK);

            chain.doFilter(req, res);
        } else {

            if (authHeader == null ) {
                throw new ServletException("Missing or invalid Authorization header");
            }

            try {
                final Claims claims = Jwts.parser().setSigningKey(SECRET_KEY).parseClaimsJws(authHeader).getBody();
                request.setAttribute("claims", claims);
            } catch (final SignatureException e) {
                throw new ServletException("Invalid token");
            }

            chain.doFilter(request, response);
        }

    }
}
